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Objectives: This study aims to conduct a thorough characterization of hand morphology. Employing a 2D geometric morphometric approach, we scrutinize individual fingers and the palm, delineating the ontogenetic trajectories for each biological sex and investigating the alterations that take place at various stages of human development., Materials and Methods: A set of thirty-two 2D anatomical landmarks were assessed in a sex-balanced sample of human hands (F = 275, M = 250 males), spanning all stages of human development. Following Procrustes registration, the data on size and shape for individual fingers and the palm were examined for each biological sex and age group. Regression analysis was utilized to quantify ontogenetic trajectories for each biological sex., Results: The findings suggest a gradual escalation in sexual dimorphism throughout human development, with statistically noteworthy distinctions becoming apparent in size starting at the age of 3, and in shape from the age of 7 onwards. Additionally, our analyses uncover a distinctive sigmoid pattern between sexes, indicating that biological male hands exhibit a sturdier build compared to biological female hands from early childhood onward., Conclusions: In conclusion, this study enriches our insights into sexual dimorphism in human hands, stressing the importance of considering both size and shape across different ontogenetic stages. These findings not only expand our understanding of human biological variation but also lay the foundation for future interdisciplinary research in diverse scientific domains., (© 2024 The Author(s). American Journal of Biological Anthropology published by Wiley Periodicals LLC.)

Statement of Problem: Studies on anthropometric measurements, one of the methods used in determining the occlusal vertical dimension, have been limited to the evaluation of only a few facial and hand parameters., Purpose: The purpose of this clinical study was to determine the possible relationships between all facial and hand measurements reported in the literature and assumed to be correlated with the occlusal vertical dimension and reveal their proportional relationships., Material and Methods: The study included a total of 271 participants, 136 women (30.37 ±8.09 years) and 135 men (30.42 ±8.49 years). A total of 36 measurements, including 4 occlusal vertical dimensions and 24 facial and 8 hand measurements, were obtained for each participant. Measurements were obtained directly from the soft tissue landmarks of the participants using 4 digital vernier calipers (Accud Digital Caliper; Accud), each designed for a different purpose. The normality of the parameters was analyzed using the Kolmogorov-Smirnov and Shapiro-Wilk tests, and the relationships between the parameters were analyzed using the Pearson correlation analysis (α=.05). Simple and multivariate linear regression analyses were also performed. Correlation coefficients were categorized as strong (r≥0.6), moderate (0.6>r>0.3), and weak (r≤0.3). Moreover, regression formulas were established for strongly correlated parameters., Results: Facial and hand measurements that showed strong correlations with occlusal vertical dimension measurements were the distance between the pupil of the eyes, the pupil of the eye-to-cheilion, sellion-to-stomion, sellion-to-labiale inferius, stomion-to-pogonion, meatus-to-exocanthion, and exocanthion-to-cheilion distances and the 4-finger width measurement between the index and little fingers., Conclusions: Certain anthropometric facial and hand measurements and regression formulas derived from the parameters that revealed strong correlations can be used to determine the occlusal vertical dimension., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Friction ridges are important and unique biometric features that have been studied in fingerprint science since antiquity and used for human identification. This study aimed to analyze palmprints and soleprints of Callithrix penicillata, including the description of flexion creases, regions, minutiae classification, and delta counting, in order to evaluate the uniqueness of these data and feasibility of using this information as an identification method. Palmprints and footprints were collected using commercial fingerprint ink on A4 size paper. Following image digitalization using the GIMP (2.10.14) image editing program, regions and flexion creases were identified. A total of 600 minutiae were classified in females (288 palms and 312 soles) and 732 in males (360 palms and 372 soles), and all deltas were counted. It was possible to identify three main inconstant flexion creases, in both palmprints and soleprints, with different distribution and orientation when compared to those in humans. Less variety in the types of minutiae and differences in the distribution of deltas were found when compared to human studies. In addition, the hypothesis of non-coincident characteristics in each sample was confirmed., (© 2024. The Author(s), under exclusive licence to Japan Monkey Centre.)

Objective: We aim to provide a teaching method to better explain the liver Couinaud Segmentation teaching., Method: Through a deep understanding of the liver Couinaud Segmentation teaching, and after more than 20 years of teaching practice, our department teaching team pioneered "Hand as Foot "., Results: The combined teaching method of "Hand as Foot" can clearly show the liver Couinaud Segmentation teaching., Conclusion: Compared with the traditional teaching method, "Hand as Foot" is favored by most teachers and students., Competing Interests: Declaration of competing interest All authors have no potential conflicts of interest to disclose., (Copyright © 2024 Asian Surgical Association and Taiwan Society of Coloproctology. Published by Elsevier B.V. All rights reserved.)

Anticipating implant sizes before total knee arthroplasty (TKA) allows the surgical team to streamline operations and prepare for potential difficulties. This study aims to determine the correlation and derive a regression model for predicting TKA sizes using patient-specific demographics without using radiographs. We reviewed the demographics, including hand and foot sizes, of 1,339 primary TKAs. To allow for comparison across different TKA designs, we converted the femur and tibia sizes into their anteroposterior (AP) and mediolateral (ML) dimensions. Stepwise multivariate regressions were performed to analyze the data. Regarding the femur component, the patient's foot, gender, height, hand circumference, body mass index, and age was the significant demographic factors in the regression analysis (R-square 0.541, p  < 0.05). For the tibia component, the significant factors in the regression analysis were the patient's foot size, gender, height, hand circumference, and age (R-square 0.608, p  < 0.05). The patient's foot size had the highest correlation coefficient for both femur (0.670) and tibia (0.697) implant sizes ( p  < 0.05). We accurately predicted the femur component size exactly, within one and two sizes in 49.5, 94.2, and 99.9% of cases, respectively. Regarding the tibia, the prediction was exact, within one and two sizes in 53.0, 96.0, and 100% of cases, respectively. The regression model, utilizing patient-specific characteristics, such as foot size and hand circumference, accurately predicted TKA femur and tibia sizes within one component size. This provides a more efficient alternative for preoperative planning., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: Swelling and edema of the hand and forearm may occur in various traumatic and degenerative diseases. So far, no precise measurement protocol exists. The objective of this study was to evaluate an examination protocol with relevant regions of interest (ROIs) measured by a 3-dimensional (3D) scanner to achieve precise, reproducible, and objective measurements for an optimized detection of volumes of the hand and forearm., Methods: A 3D scan protocol was developed using an Artec, 3D scanner EVA to measure discrete hand volumes of healthy volunteers. Five areas were defined as ROIs, representing volumes of the finger, metacarpus, wrist, hand, and distal forearm. Contralateral limbs were used for volume comparisons and calculation of volume differences., Results: For this study, 12 individuals (58.3% women, 24 hands and forearms) with a mean age of 27.1 ± 3 years were included. Mean volume values for left and right ROIs correlated with each other, with slightly higher volumes for the right upper extremity. Volume differences showed statistically significant results for the finger region (ROI I; P = .009), the metacarpal region (ROI II; P < .001), hand region (ROI IV; P = .001), and forearm region (ROI V; P = .006), with the exception of the wrist region (ROI III; P = .722)., Conclusions: Our results demonstrate that this 3D volumetric approach is a reliable and objective tool for measuring volumes and circumferences in hand and forearm. Based on our determined ROIs, further studies are needed to explore the significance for clinical applications., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The central sulcus divides the primary motor and somatosensory cortices in many anthropoid primate brains. Differences exist in the surface area and depth of the central sulcus along the dorso-ventral plane in great apes and humans compared to other primate species. Within hominid species, there are variations in the depth and aspect of their hand motor area, or knob, within the precentral gyrus. In this study, we used post-image analyses on magnetic resonance images to characterize the central sulcus shape of humans, chimpanzees (Pan troglodytes), gorillas (Gorilla gorilla), and orangutans (Pongo pygmaeus and Pongo abelii). Using these data, we examined the morphological variability of central sulcus in hominids, focusing on the hand region, a significant change in human evolution. We show that the central sulcus shape differs between great ape species, but all show similar variations in the location of their hand knob. However, the prevalence of the knob location along the dorso-ventral plane and lateralization differs between species and the presence of a second ventral motor knob seems to be unique to humans. Humans and orangutans exhibit the most similar and complex central sulcus shapes. However, their similarities may reflect divergent evolutionary processes related to selection for different positional and habitual locomotor functions., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives . This study examines the role of different machine learning (ML) algorithms to determine which socio-demographic factors and hand-forearm anthropometric dimensions can be used to accurately predict hand function. Methods . The cross-sectional study was conducted with 7119 healthy Iranian participants (3525 males and 3594 females) aged 10-89 years. Seventeen hand-forearm anthropometric dimensions were measured by JEGS digital caliper and a measuring tape. Tip-to-tip, key and three-jaw chuck pinches were measured using a calibrated pinch gauge. Subsequently, 21 features pertinent to socio-demographic factors and hand-forearm anthropometric dimensions were used for classification. Furthermore, 12 well-known classifiers were implemented and evaluated to predict pinches. Results . Among the 21 features considered in this study, hand length, stature, age, thumb length and index finger length were found to be the most relevant and effective components for each of the three pinch predictions. The k -nearest neighbor, adaptive boosting (AdaBoost) and random forest classifiers achieved the highest classification accuracy of 96.75, 86.49 and 84.66% to predict three pinches, respectively. Conclusions . Predicting pinch strength and determining the predictive hand-forearm anthropometric and socio-demographic characteristics using ML may pave the way to designing an enhanced tool handle and reduce common musculoskeletal disorders of the hand.

Purpose: Ultrasound is becoming an essential tool for hand surgeons, but most of them are trained on the job, without any diploma or dedicated training. The aim of this study was to assess the ability of hand surgeons new to ultrasound to identify hand and wrist anatomical structures., Methods: A monocentric study was conducted from January 2022 to April 2022. Ten residents and five attending hand surgeons, ultrasound novices, were involved in this study. The participants underwent two tests, wherein they were required to identify 17 anatomical structures using ultrasound, on the same subject. The second test was similar and carried out 2 to 6 weeks later by all participants. The number of structures successfully identified and if it was the case, the detection time per structure, were recorded. The correlations between participants age, years of surgical experience, surgical background (orthopedic or plastic) and the ability to perform immediately during the first test or to progress between the two tests were also assessed., Results: The average number of structures identified during the first test (T1) was 14.1+/-2.1 (82.9%), versus 16.2+/-0.8 (95.3%) structures during the second test (T2) (p = 0.001). The mean detection time per structure was 53.4 +/- 18.9 s during T1 versus 27.7 +/- 7.2 s during T2 (p < 0.0001). A moderate negative correlation between the progression in the number of anatomical structures identified between the two tests and the years of surgical experience (ρ=-0.56; p = 0.029) was found. The other parameters were neither correlated with the ability to perform at the first test nor with the progression between the two tests., Conclusion: Hand surgeons new to ultrasound are most of the time able to identify hand and wrist anatomical structures. Comparison of their first and second tests showed significant potential for improvement in anatomical structure identification and detection time of those, especially in surgeons with limited surgical experience., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Objectives: The aim of this study was to determine the relationship between the vertical mandibular ramus asymmetry and the hand measurements asymmetry in growing patients., Material and Methods: Panoramic radiographs and comparative radiographs of the right and left hands of 40 patients (14 males and 26 females) between 6 and 16 years old (mean age of 11.35±1.99 years) were evaluated. The total height of the mandibular ramus was measured, and the asymmetry index was calculated. The lengths of the proximal, middle and distal phalanges and the metacarpals of the five digits of both hands were measured and the absolute differences R-L were calculated for each one., Results: A statistically significant association between the presence of vertical mandibular ramus asymmetry and the presence of phalanges asymmetry FPII (p=0.016), FPIII (p=0.016), FPIV (p=0.033), FMIII (p=0.031) and FMIV (p=0.016) was observed., Conclusions: Mandibular asymmetry appears not to be isolated but also present in other body districts such as the phalanx bones. The total vertical asymmetry of the mandibular ramus showed an association with the asymmetry of the lengths of the FPIII, FMIII, FPIV, FMIV and FPII in growing individuals, with association between the side of mandibular asymmetry and the side of the phalanx's asymmetry. The asymmetry of this phalanges increases with increasing index of vertical mandibular ramus asymmetry.

Biometric authentication prevents losses from identity misuse in the artificial intelligence (AI) era. The fusion method integrates palmprint and palm vein features, leveraging their stability and security and enhances counterfeiting prevention and overall system efficiency through multimodal correlations. However, most of the existing multi-modal palmprint and palm vein feature extraction methods extract only feature information independently from different modalities, ignoring the importance of the correlation between different modal samples in the class to the improvement of recognition performance. In this study, we addressed the aforementioned issues by proposing a feature-level joint learning fusion approach for palmprint and palm vein recognition based on modal correlations. The method employs a sparse unsupervised projection algorithm with a "purification matrix" constraint to enhance consistency in intra-modal features. This minimizes data reconstruction errors, eliminating noise and extracting compact, and discriminative representations. Subsequently, the partial least squares algorithm extracts high grayscale variance and category correlation subspaces from each modality. A weighted sum is then utilized to dynamically optimize the contribution of each modality for effective classification recognition. Experimental evaluations conducted for five multimodal databases, composed of six unimodal databases including the Chinese Academy of Sciences multispectral palmprint and palm vein databases, yielded equal error rates (EER) of 0.0173%, 0.0192%, 0.0059%, 0.0010%, and 0.0008%. Compared to some classical methods for palmprint and palm vein fusion recognition, the algorithm significantly improves recognition performance. The algorithm is suitable for identity recognition in scenarios with high security requirements and holds practical value.

Microvascular surgery, plastic and reconstructive hand surgery, and coronary artery bypass surgery call for a microanatomical study of the branching pattern of the superficial palmar arch (SPA). For the anatomical analysis, we used a group of 20 dissected human hands injected with 4% formaldehyde solution and a 10% mixture of melted gelatin and India ink. The morphometric study was performed on 40 human hands of adult persons injected with methyl-methacrylate fluid into the ulnar and radial arteries simultaneously and afterwards corroded in 40% KOH solution for the preparation of corrosion cast specimens. The mean diameter of the SPA, between the second and third common palmar digital arteries, was 1.86 ± 0.08 mm. We identified the persistent median artery (PMA) in 5% of hands. We distinguished the three main groups of the SPAs according to variations in morphology and branching of the arch: Type 1, the long SPA; Type 2, the middle length SPA; and Type 3, the short SPA found in 27.5% of specimens. The communicating branch (CB), a vessel interconnecting the SPA to the closest branch of the radial artery, is classified into two different morphological groups. The third type of incomplete short arterial arch is the most important of the three groups of SPAs. That short SPA is potentially inadequate for restoring circulation after occlusion or radial artery harvesting for coronary artery bypass., (© 2024. The Author(s).)

The hypothenar muscle with the greatest frequency of variations is the abductor digiti minimi manus. Except for morphological variations of this muscle, have also been reported cases of an extra wrist muscle, the accessory abductor digiti minimi manus muscle. This case report presents a rare case of an accessory abductor digiti minimi muscle characterized by an unusual origin from the tendons of the flexor digitorum superficialis. This anatomical variation was identified on a formalin - fixed male cadaver of Greek origin during routine dissection. This anatomical variation, which may result in Guyon's canal syndrome or complicate common wrist and hand surgical procedures such as the carpal tunnel release, should be known to orthopaedic surgeons and hand surgeons in particular.

Through anatomical morphology, to accumulate the relevant parameters of the A1 pulley of each adult finger. A total of 100 fingers were selected, dissected layer by layer, and the A1 pulley and neurovascular of each finger were observed. Measure the length of the A1 pulley, the distance between the needle knife insertion point and the proximal edge of A1 pulley, and the nerves and blood vessels on both sides. (1) The length of A1 pulleys of each finger is 6.18 ± 0.33 mm, 6.58 ± 0.73 mm, 5.98 ± 0.67 mm, 5.36 ± 1.08 mm, 5.63 ± 1.09 mm. (2) The distances between the needle knife entry point of each finger and the volar proper nerve of the ulnar finger are 7.00 ± 1.55 mm, 8.29 ± 1.46 mm, 5.10 ± 0.25 mm, 5.30 ± 0.24 mm, 0 mm; the distances from the volar proper nerve of the radial finger are 9.08 ± 0.87 mm, 4.70 ± 1.10 mm, 7.03 ± 0.72 mm, 6.81 ± 0.22 mm, 7.81 ± 0.57 mm. (3) The distances between the needle knife entry point of each finger and the proper volar artery of the ulnar finger are 10.40 ± 0.75 mm, 8.89 ± 0.53 mm, 6.35 ± 0.44 mm, 7.26 ± 0.16 mm, 0 mm, respectively; The distances from the volar proper artery of the radial finger are 8.75 ± 1.07 mm, 6.10 ± 0.35 mm, 11.44 ± 0.41 mm, 8.19 ± 0.60 mm, 9.78 ± 0.68 mm, respectively. The landmarks of the needle entry points are located at the position corresponding to the highest point of the metacarpal heads, except the tail finger. From the needle knife entry point to distal, cut the proximal edge of the A1 pulley longitudinally along the midline until the patient can flex autonomously, and pay attention to the distance between the two sides of 3.60-11.85 mm neurovascular bundle., (© 2023. The Author(s).)

Primate fingers are typically in direct contact with the environment during both locomotion and manipulation, and aspects of external phalangeal morphology are known to reflect differences in hand use. Since bone is a living tissue that can adapt in response to loading through life, the internal bone architecture of the manual phalanges should also reflect differences in manual behaviours. Here, we use the R package Morphomap to analyse high-resolution microCT scans of hominid proximal phalanges of digits 2-5 to determine whether cortical bone structure reflects variation in manual behaviours between bipedal (Homo), knuckle-walking (Gorilla, Pan) and suspensory (Pongo) taxa. We test the hypothesis that relative cortical bone distribution patterns and cross-sectional geometric properties will differ both among extant great apes and across the four digits due to locomotor and postural differences. Results indicate that cortical bone structure reflects the varied hand postures employed by each taxon. The phalangeal cortices of Pongo are significantly thinner and have weaker cross-sectional properties relative to the African apes, yet thick cortical bone under their flexor sheath ridges corresponds with predicted loading during flexed finger grips. Knuckle-walking African apes have even thicker cortical bone under the flexor sheath ridges, as well as in the region proximal to the trochlea, but Pan also has thicker diaphyseal cortices than Gorilla. Humans display a distinct pattern of distodorsal thickening, as well as relatively thin cortices, which may reflect the lack of phalangeal curvature combined with frequent use of flexed fingered hand grips during manipulation. Within each taxon, digits 2-5 have a similar cortical distribution in Pongo, Gorilla and, unexpectedly, Homo, which suggest similar loading of all fingers during habitual locomotion or hand use. In Pan, however, cortical thickness differs between the fingers, potentially reflecting differential loading during knuckle-walking. Inter- and intra-generic variation in phalangeal cortical bone structure reflects differences in manual behaviours, offering a comparative framework for reconstructing hand use in fossil hominins., (© 2023 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.)

This study reported the body mass (BM) estimates of the Middle Miocene fossil hominoid Nacholapithecus kerioi from Africa. The average BM estimates from all forelimb and hindlimb skeletal elements was 22.7 kg, which is slightly higher than the previously reported estimate of ~22 kg. This study revealed that Nacholapithecus has a unique body proportion with an enlarged forelimb relative to a smaller hindlimb, suggesting an antipronograde posture/locomotion, which may be related to the long clavicle, robust ribs, and some hominoid-like vertebral morphology. Because the BM of Nacholapithecus in this study was estimated to be below 30 kg, Nacholapithecus probably did not have relatively shorter and robust femora, which may result from other mechanical constraints, as seen in extant African hominoids. The BM estimate of Nacholapithecus suggests that full substantial modifications of the trunk and forelimb anatomy for risk avoidance and foraging efficiency, as seen in extant great apes, would not be expected in Nacholapithecus. Because larger monkeys are less arboreal (e.g., Mandrillus sphinx or Papio spp.), and the maximum BM among extant constant arboreal cercopithecoids is ~24 kg (male Nasalis larvatus), Nacholapithecus would be a constant arboreal primate. Although caution should be applied because of targeting only males in this study, arboreal quadrupedalism with upright posture and occasional antipronograde locomotion (e.g., climbing, chambering, descending, arm-swing, and sway) using the powerful grasping capacity of the hand and foot may be assumed for positional behavior of Nacholapithecus., (© 2023 American Association for Anatomy.)

The increase in repetitive strain injuries to the hand underscores the need for assessing and preventing musculoskeletal overuse associated with hand-intensive tasks. This study investigates the risk of overload injuries in soft tissue structures of the hand by analyzing the pressure distribution and location of peak pressure in the hand during snap-fit connection assembly in the automotive industry. The influence of the surface geometry of automotive trim components the pressure distribution and force imparted during strikes with the palm and the fist are investigated in a cohort of 30 subjects with extensive experience installing trim parts with snap-fit connections. Using the palm or fist (ulnar hand side) of the dominant hand, the subjects struck a simulation device with a flat, rounded, or edged surface geometry. The average peak force applied was 600 N (±122 N), nearly 3 times the force required to overcome the technical resistance of the snap-fit connector (220 N). Fist strikes exerted a 40% higher mean peak pressure and 18% higher mean pressure than did palm strikes. The pressure distribution in the region of the thenar eminence and soft tissue of the ulnar side of the hand did not differ between fist strikes on flat and edged surfaces. Considering the delicate anatomy of the hand, especially the hypothenar muscles on the ulnar side, assembling connection claps using the fist instead of the palm may prevent repetitive blunt trauma to the sensitive blood vessels and nerves in the palm.

Multimodal biometric systems are often used in a wide variety of applications where high security is required. Such systems show several merits in terms of universality and recognition rate compared to unimodal systems. Among several acquisition technologies, ultrasound bears great potential in high secure access applications because it allows the acquisition of 3D information about the human body and is able to verify liveness of the sample. In this work, recognition performances of a multimodal system obtained by fusing palmprint and hand-geometry 3D features, which are extracted from the same collected volumetric image, are extensively evaluated. Several fusion techniques based on the weighted score sum rule and on a wide variety of possible combinations of palmprint and hand geometry scores are experimented with. Recognition performances of the various methods are evaluated and compared through verification and identification experiments carried out on a homemade database employed in previous works. Verification results demonstrated that the fusion, in most cases, produces a noticeable improvement compared to unimodal systems: an EER value of 0.06% is achieved in at least five cases against values of 1.18% and 0.63% obtained in the best case for unimodal palmprint and hand geometry, respectively. The analysis also revealed that the best fusion results do not include any combination between the best scores of unimodal characteristics. Identification experiments, carried out for the methods that provided the best verification results, consistently demonstrated an identification rate of 100%, against 98% and 91% obtained in the best case for unimodal palmprint and hand geometry, respectively.

The importance of dynamometric and anthropometric information for industry is known; however, few studies have investigated the relationship between anthropometry and handgrip strength (HGS) in adolescents. The aim of the present study was to investigate the association of anthropometric variables with the level of HGS production in adolescents. Participants were 541 adolescents aged 12-16 years from a public school in the city of Rio de Janeiro. The behavior of the following variables was examined: the ability to generate HGS, age, total body mass, height and hand dimensions (hand width, hand span, hand length). The results showed an increase in the ability to generate HGS in adolescence and a significant difference between the genders from 13 years old, where boys generated higher HGS values. Correlations between HGS and total body mass and the hand width stood out in both genders, indicating a greater association.

Background: The hand anthropometric data is the baseline for design of hand tools and equipment., Objective: This study aimed to generate the hand anthropometric database of male and female agricultural workers and compare it with the hand anthropometric data of other regions of India. The use of collected data is illustrated to design hand tools and protective gear., Methods: Hand anthropometric data were collected from 228 male and 198 female agricultural workers of northeast India. A total of 35 hand dimensions, stature and body mass from different tribes in the age group of 18-60 years were precisely measured. Measured data were statistically analysed to study the effects of gender, ethnicity, and age on hand dimensions. Correlation coefficients were determined among hand dimensions and linear regression equations were developed between highly correlated dimensions., Results: The results show that all hand dimensions of the male and female subjects are significantly different (p < 0.01). Most of the hand dimensions were significantly different (p < 0.05) among different tribes for the male subjects. However, less number of hand dimensions were significantly different among tribes for the female subjects. Age of the subjects has significant effects (p < 0.01) on dimensions related to thickness, depth and circumference of fingers. The use of these data in the ergonomic design of hand tools and personal protective gear is illustrated to increase safety and comfort as well as efficiency of operators., Conclusion: There is a difference in the hand dimensions of different tribes of northeast India. This needs to be considered when designing agricultural hand tools and equipment.

Background and Objective: Various aspects of fingerprint resarch were extensively explored in the past. However, the correlation between fingerprint ridge density and hand dimensions has not yet been documented. Therefore, the present study has investigated the relationship so that some conclusions regarding the association can be established., Methods: The study included 500 subjects (250 males and 250 females) between the ages of 18 to 25 years who belonged to the Rajput community of the Shimla and Solan districts of Himachal Pradesh state of North India. The sexual dimorphism among the ridge count was examined using student's t-test. The relationship of fingerprint ridge density with hand dimensions among both the sexes and pooled data was analyzed using Pearson's correlation coefficient., Results: All the fingers on both hands showed statistically significant sex differences. When all digits were considered together, the left little finger in males and right middle finger in females showed a weak but significant correlation with hand length while all the digits when considered in combination reported strong correlation hand length measurements. Similarly, right thumb showed significant correlation with hand breadth. All the ten digits showed highly significant correlation with hand breadth when pooled data was examined., Conclusion: The ridge density correlates with the hand dimensions in the case of pooled data. This relationship can then be used to devise prediction equations for hand dimensions based on ridge density, or vice-versa for pooled data. The equations will also help in estimating hand dimensions based on ridge density and vice-versa.

Background: Determination of sex from mutilated body fragments can perform vital role for identification of departed soul. Forensic authority pacts with human identification from the hand measurements which is of prodigious assessment during tragedies, terror attacks and in criminality., Objective: Present study explored the analytical role of the anthropometric measurements of hand dimensions, find demarking points for male and female, check percentage exactitude of sex determination in Western Indian population., Methods: The study was piloted on a sample of 504 individuals. All the measurements were taken by standard procedure. Discriminant analysis and demarking points were created for all hand measurements., Results: Males have a significantly higher values of all measurements than females. The left-hand length measurement unveiled a noteworthy sexual dimorphism index (110.80). The higher value of the demarking point labelled as males. The best sexually dimorphic hand dimensions showed the utmost precision left hand length (95% in the male), followed by right hand length (76.1%)., Conclusion: All hand measurements like length, breadth and index are displaying sexual dimorphism, hence they can be used for determination of sex when isolated hand is found., (© 2022 Gupta R et al.)

We investigated whether brief non-judgmental focus on the details of one's non-dominant hand might lead to changes in perception of its size, and if such a change would be related to central coherence, body dissatisfaction, or how much participants liked their hand. After two pilot experiments (N = 28 and N = 30 respectively: Appendix 1), a within-subject experiment (N = 82) was conducted. Subjects were mainly university students. They were asked to rate the size of their non-dominant hand and how much they liked it, and the size of an external object (a X-box controller) on a visual-analog scale before and after focusing on their details for 5 min, as well as the size of another object (a calculator) before and after a 5 min long distraction task. After completing the tasks, they were asked to respond to a brief questionnaire on body dissatisfaction. A s significant interaction between time and factors (non-dominant hand, X-box controller and calculator) emerged (F(2, 78) = 6.41, p = .003). Participants rated their hand as larger after focusing on its details compared to baseline, and this change was significantly larger than those reported for the X-box controller. No significant change in how they liked their hand was observed, and contrary to the pilot experiments, the perceived change in size of the hand was not related to body dissatisfaction. The significant change in reporting of the size of the hand after focusing on its details seems to be an interesting finding, worth further replications., (© 2022. The Author(s).)

Background: Lumbrical muscles originate in the palm from the 4 tendons of the flexor digitorum profundus and course distally along the radial side of the corresponding metacarpophalangeal joints, in front of the deep transverse metacarpal ligament. The first and second lumbrical muscles are typically innervated by the median nerve, and third and fourth by the ulnar nerve. A plethora of lumbrical muscle variants has been described, ranging from muscles' absence to reduction in their number or presence of accessory slips. The current cadaveric study highlights typical and variable neural supply of lumbrical muscles., Materials: Eight (3 right and 5 left) fresh frozen cadaveric hands of 3 males and 5 females of unknown age were dissected. From the palmar wrist crease, the median and ulnar nerve followed distally to their terminal branches. The ulnar nerve deep branch was dissected and lumbrical muscle innervation patterns were noted., Results: The frequency of typical innervations of lumbrical muscles is confirmed. The second lumbrical nerve had a double composition from both the median and ulnar nerves, in 12.5% of the hands. The thickest branch (1.38 mm) originated from the ulnar nerve and supplied the third lumbrical muscle, and the thinnest one (0.67 mm) from the ulnar nerve and supplied the fourth lumbrical muscle. In 54.5%, lumbrical nerve bifurcation was identified., Conclusion: The complex innervation pattern and the peculiar anatomy of branching to different thirds of the muscle bellies are pointed out. These findings are important in dealing with complex and deep injuries in the palmar region, including transmetacarpal amputations.

Objectives. This study aimed to investigate the relationship between dentists' hand functionality (handgrip, tip-to-tip pinch, key pinch and palmar pinch strengths) and dental specialty (maxillofacial surgery, endodontics, pediatric dentistry), socio-demographic factors and hand-forearm anthropometric dimensions. Methods. A cross-sectional study was designed in which 720 certified dentists (330 males and 390 females) voluntarily participated in the study. A tape measure (±0.1 cm) and a digital caliper (±0.1 mm) were used to measure anthropometric dimensions. A Jamar dynamometer and pinch gauge were used to measure hand strength variables. Results. Hand strengths decreased with age and clinical experience, and were always greater in male than female dentists. Maxillofacial surgeons aged 35-39 years attained the highest values of handgrip and key pinch strengths, while endodontists aged 30-34 years attained the peak values of tip-to-tip pinch strength. Among the measured hand dimensions, forearm circumference was significantly greater in maxillofacial surgeons compared with endodontists and pediatric dentists. Conclusion. Hand functionality is specialty-related among dentists because distinct dental specialties expose practitioners to different task demands. Like any other manual workers, dentists need more ergonomic and usable hand tools tailored not only to the intended application but also to the anthropometry of users.

Heterogeneous palmprint recognition has attracted considerable research attention in recent years because it has the potential to greatly improve the recognition performance for personal authentication. In this article, we propose a simultaneous heterogeneous palmprint feature learning and encoding method for heterogeneous palmprint recognition. Unlike existing hand-crafted palmprint descriptors that usually extract features from raw pixels and require strong prior knowledge to design them, the proposed method automatically learns the discriminant binary codes from the informative direction convolution difference vectors of palmprint images. Differing from most heterogeneous palmprint descriptors that individually extract palmprint features from each modality, our method jointly learns the discriminant features from heterogeneous palmprint images so that the specific discriminant properties of different modalities can be better exploited. Furthermore, we present a general heterogeneous palmprint discriminative feature learning model to make the proposed method suitable for multiple heterogeneous palmprint recognition. Experimental results on the widely used PolyU multispectral palmprint database clearly demonstrate the effectiveness of the proposed method.

Purpose: For many years, it was thought that the thumb consists of just two phalanges that differentiate it from the other four medial triphalangeal fingers. But there are some old reports that few former scientists believed the thumb has three phalanges and it lacked a metacarpal, and the thumb metacarpal is a phalanx. So this anthropometric study was carried out by investigating the morphology of the long bones of the hand and correlations between the thumb metacarpal and other miniature long bones of the hand., Methods: We studied anterior-posterior X-ray images of the right hands of 80 individuals from 18 to 65 years old. The exploration targets were the length of all metacarpals (MC), proximal phalanges (PP), middle phalanges (MP), and distal phalanges (DP). Friedman Repeated Measures Analysis of Variance and Dunn's post hoc test were carried out to compare the means of all variables. The correlation between all quantitative factors was done by Spearman Rank Correlation (Spearman's Rho) coefficient., Results: Our results showed that the length of the phalanges and the total length of the fingers are independent of the related metacarpal length (P < 0.001). Also, the thumb metacarpal length in comparison to all bones of the hand was significantly different from all long bones of the hand except the proximal phalanx of the middle finger (P = 1)., Conclusion: Based on the morphology of the long bones of the hand and the high similarity between the thumb metacarpal and phalanges especially the proximal phalanx of the middle finger, it can be suggested that the current thumb metacarpal is a proximal phalanx of the thumb., (© 2022. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background and Aim: Anthropometry is widely used in preliminary forensic investigations involving the identification of unknown dismembered body parts. Stature estimation is an important indicator of forensic identification considered during such initial investigations. Different populations have different body sizes and proportions that affect the forensic anthropometric estimation of stature. Hence, the need for population-specific databases and analyses. The present study was conducted with the objective of estimating stature from the hand dimensions in the Eastern Saudi Arabian adult male population., Methods: The present study included 200 Eastern Saudi Arabian males aged from 20 to 56 years. Stature and hand dimensions of hand length, palm length, and hand breadth were measured as per standard anthropometric procedures. Linear and multiple regression equations were derived to estimate stature from the aforementioned hand dimensions., Results: Correlation coefficients between stature and the aforementioned hand dimensions were found to be statistically significant. The hand length and palm length showed higher correlation coefficients than the hand breadth. Single variable linear regression and multi-variable linear regression equations were derived to estimate stature from the hand dimensions. Higher correlation coefficients were obtained for multi-variable linear regression than single variable linear regressions., Conclusions: In conclusion, hand dimensions can be used as a reliable predictor to estimate stature in the Eastern Saudi Arabian adult male population. (www.actabiomedica.it).

Automatic identity verification is one of the most critical and research-demanding areas. One of the most effective and reliable identity verification methods is using unique human biological characteristics and biometrics. Among all types of biometrics, palm print is recognized as one of the most accurate and reliable identity verification methods. However, this biometrics domain also has several critical challenges: image rotation, image displacement, change in image scaling, presence of noise in the image due to devices, region of interest (ROI) detection, or user error. For this purpose, a new method of identity verification based on median robust extended local binary pattern (MRELBP) is introduced in this study. In this system, after normalizing the images and extracting the ROI from the microscopic input image, the images enter the feature extraction step with the MRELBP algorithm. Next, these features are reduced by the dimensionality reduction step, and finally, feature vectors are classified using the k-nearest neighbor classifier. The microscopic images used in this study were selected from IITD and CASIA data sets, and the identity verification rate for these two data sets without challenge was 97.2% and 96.6%, respectively. In addition, computed detection rates have been broadly stable against changes such as salt-and-pepper noise up to 0.16, rotation up to 5°, displacement up to 6 pixels, and scale change up to 94%., (© 2021 Wiley Periodicals LLC.)

The knuckle creases present on the dorsal side of the human hand can play significant role in identifying the offenders of serious crime, especially when evidence images of more recognizable biometric traits, such as the face, are not available. These knuckle creases, if localized appropriately, can result in improved identification ability. This is attributed to ambient inclusion of the creases and minimal effect of background, which lead to quality and discerning feature extraction. This paper presents an ensemble approach, utilizing multiple object detector frameworks, to localize the knuckle regions in a functionally appropriate way. The approach leverages from the individual capabilities of the popular object detectors and provide a more comprehensive knuckle region localization. The investigations are completed with two large-scale public hand databases which consist of hand-dorsal images with varying backgrounds and finger positioning. In addition to that, effectiveness of the proposed approach is also tested with a novel proprietary unconstrained multi-ethnic hand dorsal dataset to evaluate its generalizability. Several novel performance metrics are tailored to evaluate the efficacy of the proposed knuckle localization approach. These metrics aim to measure the veracity of the detected knuckle regions in terms of their relation with the ground truth. The comparison of the proposed approach with individual object detectors and a state-of-the-art hand keypoint detector clearly establishes the outperforming nature of the proposed approach. The generalization of the proposed approach is also corroborated through the cross-dataset framework.

Accurate knowledge of the technique of ultrasonographic (US) examination and of normal US appearance is a prerequisite for a successful US examination of the wrist and hand. In this article, we describe our standard US examination as well as the normal US findings of the hand and wrist., Competing Interests: Disclosures of conflicts of interest V. Créteur disclosed no relevant relationships. A. Madani disclosed no relevant relationships. S. Bianchi disclosed no relevant relationships., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: The anatomical structures in relation to the carpal tunnel release are the palmaris brevis muscle (PBM), transverse carpal ligament (TCL), and the recurrent motor branch of the median nerve (RMBMN). Our aim is to describe the gross morphology in the Korean population of the PBM, TCL, and RMBMN specifically looking for anomalies, and to determine the muscles encountered during a standard carpal tunnel release. Material and Methods: A total of 30 cadaveric hands were dissected. A longitudinal line drawn from the third web space to the midpoint of the distal wrist crease served as the reference line (RL). The PBM and TCL were classified according to its shape and location. The length, width, and thickness of the TCL were measured. The ratio of the lengths of PBM and TCL to RL was calculated. The course of the RMBMN was dissected specifically looking for anomalies. We also looked at the muscle fibers encountered during a standard carpal tunnel release to identify the muscle. Results: PBM was classified into three different types based on the shape. The average thickness of the PBM and TCL were 0.89 ± 0.16 mm and 1.43 ± 0.40 mm, respectively. The distal border of the TCL was thicker than the proximal border. The average ratio of the length of the PBM to the RL was 25.65 ± 8.62% and TCL to the RL was 24.00 ± 3.37%. The distribution of the RMBMN was classified into three different types. A few accessory branches of the RMBMN were also noted. And 36 muscle fibers were noted within the TCL in line with the RL. Conclusion: We clarified findings and added quantitative information about the anatomical structures surrounding carpal tunnel. A thorough knowledge of the anatomy and anomalies around the carpal tunnel is helpful for surgeons to ensure optimal surgical results.

Biometric signals can be acquired with different sensors and recognized in secure identity management systems. However, it is vulnerable to various attacks that compromise the security management in many applications, such as industrial IoT. In a real-world scenario, the target template stored in the database of a biometric system can possibly be leaked, and then used to reconstruct a fake image to fool the biometric system. As such, many reconstruction attacks have been proposed, yet unsatisfactory naturalness, poor visual quality or incompleteness remains as major limitations. Thus, two reinforced palmprint reconstruction attacks are proposed. Any palmprint image, which can be easily obtained, is used as the initial image, and the region of interest is iteratively modified with deep reinforcement strategies to reduce the matching distance. In the first attack, Modification Constraint within Neighborhood (MCwN) limits the modification extent and suppresses the reckless modification. In the second attack, Batch Member Selection (BMS) selects the significant pixels (SPs) to compose the batch, which are simultaneously modified to a slighter extent to reduce the matching number and the visual-quality degradation. The two reinforced attacks can satisfy all the requirements, which cannot be simultaneously satisfied by the existing attacks. The thorough experiments demonstrate that the two attacks have a highly successful attack rate for palmprint systems based on the most state-of-the-art coding-based methods.

Robotic hands perform several amazing functions similar to the human hands, thereby offering high flexibility in terms of the tasks performed. However, developing integrated hands without additional actuation parts while maintaining important functions such as human-level dexterity and grasping force is challenging. The actuation parts make it difficult to integrate these hands into existing robotic arms, thus limiting their applicability. Based on a linkage-driven mechanism, an integrated linkage-driven dexterous anthropomorphic robotic hand called ILDA hand, which integrates all the components required for actuation and sensing and possesses high dexterity, is developed. It has the following features: 15-degree-of-freedom (20 joints), a fingertip force of 34N, compact size (maximum length: 218 mm) without additional parts, low weight of 1.1 kg, and tactile sensing capabilities. Actual manipulation tasks involving tools used in everyday life are performed with the hand mounted on a commercial robot arm., (© 2021. The Author(s).)

The hand endows us with unparalleled precision and versatility in our interactions with objects, from mundane activities such as grasping to extraordinary ones such as virtuoso pianism. The complex anatomy of the human hand combined with expansive and specialized neuronal control circuits allows a wide range of precise manual behaviours. To support these behaviours, an exquisite sensory apparatus, spanning the modalities of touch and proprioception, conveys detailed and timely information about our interactions with objects and about the objects themselves. The study of manual dexterity provides a unique lens into the sensorimotor mechanisms that endow the nervous system with the ability to flexibly generate complex behaviour., (© 2021. Springer Nature Limited.)

Abstract: Carpal tunnel syndrome (CTS) is a common neuropathy. Although CTS progression is known to be associated with thenar muscle (TM) atrophy, the diagnostic value of TM atrophy for CTS has not been established. In this research, the thenar muscle cross-sectional area (TMCSA) was evaluated to analyze the relationship between the TMCSA and CTS. We assumed that TMCSA is a major diagnostic parameter in the CTS.Both TMCSA and thenar muscle thickness (TMT) samples were acquired from 18 CTS patients, and from 18 control subjects who underwent wrist magnetic resonance imaging with no evidence of CTS. T2-weighted transverse magnetic resonance imaging images were obtained. We measured the TMCSA and TMT at the level of first carpometacarpal joint.The average TMCSA was 296.98 ± 49.39 mm2 in the normal group and 203.36 ± 72.13 mm2 in the CTS group. The average TMT was 8.54 ± 1.45 mm in the normal group and 7.38 ± 1.14 mm in the CTS group. CTS group had significantly lower TMCSA and TMT. Receiver operator characteristics curve analysis showed that the best cutoff point for the TMCSA was 260.18 mm2, with 77.8% sensitivity, 77.8% specificity. The best cutoff point of the TMT was 7.70 mm, with 61.1% sensitivity, 66.7% specificity.Although the TMCSA and TMT were both significantly associated with CTS, the TMCSA was a much more sensitive measurement parameter. Thus, to evaluate CTS patients, the physician should more carefully inspect the TMCSA than TMT., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Body representation distortion (BRD) is a core criterion of Anorexia Nervosa (AN), and is usually assessed subjectively, focusing on body shape. We aimed to develop a new assessment to evaluate body representation independently from socially-mediated body image, on a body part with low emotional salience (hands). In a monocentric open label pilot study, we measured hand representations based on explicit (verbal) and implicit (tactile) instructions. Participants, with eyes closed, had to point targeted locations (knuckles and nails of each finger) based on verbal instructions and tactile stimulations to evaluate body representations respectively. Ratios between hand width and finger length were compared between AN (n = 31) and controls (n = 31) and correlated with current body mass index, AN subtype and disease duration. To control that hand distortion was specific to body representation, we also assessed object representation. Hand representation's width/length ratio was significantly increased in patients with AN, whereas no difference was found in object representation. We found no correlation between hand wideness and clinical traits related to eating disorders. Our results propose that BRD is not limited to body parts with high emotional salience, strengthening the hypothesis that anorexia nervosa is associated with profound unspecific BRD., (© 2021. The Author(s).)

Competing Interests: The author declares no conflicts of interest.

Objectives: Ultra-high frequency ultrasonography (UHFUS) is a recently introduced diagnostic technique which finds several applications in diverse clinical fields. The range of frequencies between 30 and 100 MHz allows for high spatial resolution imaging of superficial structures, making this technique suitable for the imaging of skin, blood vessels, musculoskeletal anatomy, oral mucosa, and small parts. However, the current clinical applications of UHFUS have never been analyzed in a consistent multidisciplinary manner. The aim of this study is to revise and discuss the current applications of UHFUS in different aspects of research and clinical practice, as well as to provide some examples of the current work-in-progress carried out in our center., Materials and Methods: A literature search was performed in order to retrieve articles reporting the applications of UHFUS both in research and in clinical settings. Inclusion criteria were the use of frequencies above 30 MHz and study design conducted in vivo on human subjects., Results: In total 66 articles were retrieved. The majority of the articles focused on dermatological and vascular applications, although musculoskeletal and intraoral applications are emerging fields of use. We also describe our experience in the use of UHFUS as a valuable diagnostic support in the fields of dermatology, rheumatology, oral medicine, and musculoskeletal anatomy., Conclusion: Ultra-high frequency ultrasonography application involves an increasing number of medical fields. The high spatial resolution and the superb image quality achievable allow to foresee a wider use of this novel technique, which has the potential to bring innovation in diagnostic imaging.

Palmprint recognition has received tremendous research interests due to its outstanding user-friendliness such as non-invasive and good hygiene properties. Most recent palmprint recognition studies such as deep-learning methods usually learn discriminative features from palmprint images, which usually require a large number of labeled samples to achieve a reasonable good recognition performance. However, palmprint images are usually limited because it is relative difficult to collect enough palmprint samples, making most existing deep-learning-based methods ineffective. In this paper, we propose a heuristic palmprint recognition method by extracting triple types of palmprint features without requiring any training samples. We first extract the most important inherent features of a palmprint, including the texture, gradient and direction features, and encode them into triple-type feature codes. Then, we use the block-wise histograms of the triple-type feature codes to form the triple feature descriptors for palmprint representation. Finally, we employ a weighted matching-score level fusion to calculate the similarity between two compared palmprint images of triple-type feature descriptors for palmprint recognition. Extensive experimental results on the three widely used palmprint databases clearly show the promising effectiveness of the proposed method.

Background: Volumetric rejuvenation of the dorsum of the hand with fat grafting or injectable fillers has increased in popularity in recent years. It has become widely accepted that the dorsum of the hand contains three fatty laminae: superficial, intermediate, and deep laminae. The dorsal venous plexus and dorsal cutaneous nerves are known to reside in the dorsal intermediate lamina. However, the superficial vein and cutaneous nerve might not be located in the same layer of subcutaneous tissue, as is the case in other body regions., Materials and Methods: Eight hands were dissected in a layer-by-layer fashion from the skin to the extensor tendons. In another 13 hands from among 21 investigated cadavers, samples from the dorsum of the hand were harvested and stained using trichrome stains for histologic analysis. B-mode ultrasound was also performed for identifying structures of the dorsum of the hand., Results: Anatomic dissection and histologic analysis of the dorsum of the hand revealed the presence of an unknown fascia in addition to the three known fascial layers. The additional fascia was located in the dorsal intermediate lamina and separated it into two compartments: one containing the dorsal venous plexus superficially and the other containing the dorsal cutaneous nerves deeply. Ultrasound showed corresponding structures including three hyperechoic fascial layers, three hypoechoic laminae, and additional hyperechoic fascia in dorsal intermediate lamina., Conclusions: Accurate anatomic knowledge of the dorsum of the hand will help practitioners determine the optimal and safe locations for performing fat grafting and injecting dermal fillers., (Copyright © 2020 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)